The overall goal of this study is to make a contribution to understanding interaction in the stepfamily, with particular emphasis on the psychological well-being of children. Research has not kept pace with the increasing number of children and adults who live in stepfamilies. The objectives of the present study, therefore, are: 1) to contribute to the development of basic information about the structure and function of the stepfamily, describing stepparents' and stepchildren's views of each other's behavior, and 2) to advance current understanding about the mental health of stepchildren, developing profiles reflecting critical stepparent-stepchild interactions. The first objective, contribution to the development of basic information about the stepfamily, will be pursued by collecting data in areas where no systematic body of knowledge is extant. Data to be obtained include descriptions of the composition of the separate households of biological parents and visiting patterns between the child and the nonresident parent. A typology of arrangements in which children are likely to live and visit will be presented, and the quantitative relationship of various aspects of this typology to other variables and to child adjustment will be explored. More importantly, complementary information about stepparents' and children's views of one another's behavior will be obtained, and descriptions of salient positive and negative dyadic interactions will be collected and categorized. Systematizing self-reports from all relevant role incumbents is expected to yield a set of variables characteristic of stepfamily lifestyle. The second research objective will be met by investigating the relationship of each class of stepfamily variables to child outcomes and through regression analysis organizing the most influential among them into a model predictive of stepchild adjustment.